The stone mass seems to rise, almost weightlessly, to the baldachin, 43 m high arches. The narrow main nave, which leads to the chancel is accompanied by two side naves. In the northern side nave the light shines through five glorious glass windows, which stem from the later years of Cologne glass painting (1507/1509).
In the crossing the modern bronze altar from Elmar Hillebrand (1960) can be found. Behind this there is the high chancel with the choir ambulatory, which is one of the finest sacral rooms of the Western world. The chancel seating is the largest in Germany with 104 seats.
Around 1340 the chancel closet paintings were made. Above these there are the older chancel pillar sculptures of Jesus, Mary and the Twelve Apostles. The entire circle of glass windows in the upper floor of the central nave also shows 48 royal figures in addition to the worship of the Three Magi.
Behind the high altar the Shrine to the Three Magi rises up, where the relics of the city patrons and the Holy Felix, Nabor and Gregor von Spoleto rest. This impressive work of medieval gold craftsmanship exceeds all other shrines of the western world in terms of size and glory (6 hundredweight, 153 cm high, 220 cm long, 110 cm wide).
The way to the choir ambulatory leads to the left under the organ stage. The Gero Crucifix is hanging in the crucifix chapel and is the oldest remaining large crucifix sculpture on this side of the Alps. In the axis chapel (Chapel of the Three Magi) the oldest window in the Cathedral (around 1260) can still be found in its original place. It shows scenes from the New and the Old Testament in two parallel rows, which are linked to each other. Another large work of art can be found in the chancel of Mary’s Chapel. It is a triple winged altar picture (triptych), painted by Stefan Lochner for the Town Hall chapel.
The city’s saints are thus represented: the Three Magi, Saint Ursula and Saint Gereon with their martyrs. On the one hand the work documents the exceptional artistic personality of Stefan Lochner, on the other hand also the high self esteem of Cologne at that time (mid-15th century).